System, method and apparatus for link training during a clock switch event
AssigneeIntel Corporation
InventorsEhud Shoor, Tsion Vidal, Uri Hermoni, Efraim Kugman, Sarel Wechsler, Oren Salomon, Golan Cohen
Life of this patent
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Abstract
In one embodiment, an apparatus comprises: a receiver to receive training data from a transmitter; a clock and data recovery (CDR) circuit coupled to the receiver, the CDR circuit to recover a recovered clock signal from the training data; and a media access control (MAC) circuit coupled to the CDR circuit, wherein the MAC circuit is to send a clock switch indicator to the CDR circuit to cause the CDR circuit to halt tracking operation of the CDR circuit. Other embodiments are described and claimed.
Claims15
An apparatus comprising:
- a receiver to receive training data from a transmitter;
- a clock and data recovery (CDR) circuit coupled to the receiver, the CDR circuit to recover a recovered clock signal from the training data;
- and
- a media access control (MAC) circuit coupled to the CDR circuit, wherein the MAC circuit is to send a clock switch indicator to the CDR circuit to cause the CDR circuit to halt tracking operation of the CDR circuit;
- wherein:
- the apparatus comprises a re-timer;
- the re-timer comprises:
- a physical (PHY) circuit comprising the receiver and the CDR circuit;
- and
- a link layer circuit coupled to the PHY circuit, the link layer circuit comprising the MAC circuit;
- and
- the re-timer is to send a clock switch request to the transmitter when the MAC circuit detects the training data.
A method comprising:
- receiving, in a receiver circuit, training data from a transmitter;
- detecting that a clock switch event has occurred in the transmitter;
- in response to detecting that the clock switch event has occurred, halting a tracking mode of a clock and data recovery (CDR) circuit;
- and
- receiving the training data from the transmitter, the training data generated in the transmitter according to a local clock signal, the transmitter comprising a first re-timer, the first re-timer coupled to a second re-timer, and the second re-timer comprising the receiver circuit.
A system comprising:
- a host device;
- a device coupled to the host device via a link;
- and
- at least one re-timer coupled between the host device and the device, wherein the at least one re-timer comprises:
- a receiver to receive training data from a transmitter;
- a clock and data recovery (CDR) circuit coupled to the receiver, the CDR circuit to recover a recovered clock signal from the training data;
- and
- a media access control (MAC) circuit coupled to the CDR circuit, wherein the MAC circuit is to send a clock switch indicator to the CDR circuit to cause the CDR circuit to halt tracking operation of the CDR circuit during a clock switch event in the transmitter, and the MAC circuit comprises a clock switch detector to detect the clock switch event based at least in part on a loss of the training data.
Dependencies are inferred from the claim text.